The combination switch is fitted to the vicinity of a steering wheel of a steering column of an automobile. The combination switch is a switch unit configured to combine a plurality of switches such as a lighting switch and a windscreen wiper switch having functions different from each other into one integral unit. A fitting structure for fitting the combination switch to the steering column is, as disclosed in Japanese Patent Application Laid-Open No. 2000-3638, such that an inner peripheral surface of a fitting portion provided in the combination switch is fitted onto an outer peripheral surface of the steering column, thus making the steering column concentric with the combination switch. Further, the combination switch is positioned in an axial direction with respect to the steering column by abutting an end face of the combination switch against an end face of the steering column, and is also positioned and fixed in a rotating direction with respect to the steering column by fastening the combination switch to a fitting bracket with bolts, which bracket is fixed by welding to the steering column.
It is desirable for reducing a manufacturing cost of the combination switch that the combination switch having the same or common specifications is used in common to multiple types of cars. In a conventional method of fitting the inner peripheral surface of the combination switch onto the outer peripheral surface of the steering column, however, it is required that the combination switch used in common can be fitted to the steering column for a heavy duty or large-sized vehicle. If so, the dimensions of the outer diameters of the steering column and the steering shaft for even a small-sized vehicle are required to be equal to those for the heavy duty or large-sized vehicle, resulting in an excess over the optimum dimensions for the small-sized vehicle. Therefore, the steering apparatus increases in weight, and resultantly there is a possibility that the manufacturing cost of the whole steering apparatus increases.